For the study, published in the Journal of Clinical Endocrinology & Metabolism, the team evaluated the frequency of menstrual irregularity in girls with recently diagnosed diabetes and whether the addition of intensive lifestyle or rosiglitazone to previous treatment with metformin helped to improve symptoms.

These treatments are often used to treat both diabetes and PCOS.

The researchers found that more than 20 per cent of girls had irregular periods. Many of those girls also had high testosterone levels, pointing to PCOS as an underlying cause.

However, not all the girls with irregular periods had elevated testosterone, suggesting other causes for menstrual dysfunction, including pregnancy, hormonal imbalances, infections, diseases, trauma and certain medications.

"Our findings suggest that girls with youth-onset diabetes may need the additional intervention above and beyond their diabetes treatment to improve their menstrual health," Kelsey said.